Clint Dempsey of the Sounders shredded a referee’s notebook. / Drew Sellers, Sportspress Northwest

Tuesday night’s 3-1 loss to the Portland Timbers at the Starfire Sports Complex ended abruptly the Sounders’ chances of winning a record fifth U.S. Open Cup. But the more important issues are the status of midfielder Clint Dempsey and forward Obafemi Martins, neither of whom saw the end of a wild match that concluded with Seattle down to seven players.

Dempsey potentially faces a ban from U.S. Soccer of three months or longer, according to The Washington Post, for snatching referee Daniel Radford’s notebook and tearing it up, an action that U.S. Soccer could view as “referee assault.” Still not recovered from nasal surgery, Martins was carted off on a stretcher in extra time with an apparent groin injury. An MRI will determine his status.

Soccer Federation policy states that “damaging the referee’s uniform or personal property” is considered referee assault, which draws a minimum three-month ban.

The fourth round of the U.S. Open Cup was marked by eight total bookings and three ejections, all of the ousters involving Sounders’ players, beginning with a second yellow card issued to Brad Evans in the 69th minute with Portland leading 1-0 on a goal by Diego Valeri.

Despite playing with 10 men following Evans’ ejection (he drew his first yellow in the 38th minute), Martins equalized the match in the 79th following a corner kick by Dylan Remick. Martins suffered his injury shortly thereafter, leaving Seattle with nine players heading into extra time.

After Portland reclaimed the lead on a Rodney Wallace goal in the 100th minute, the Sounders lost Michael Azira to a red card following a foul on Gaston Fernandez. Dempsey quickly came to Azira’ defense and Radford showed him a yellow. Video  of the incident appears to show that Dempsey then snatched the card book out of Radford’s pocket and tossed it to the turf. Dempsey then picked it up and ripped it in half.

Down to six players and a goalkeeper, the Sounders ceded a final goal to Maximiliano Urruti, setting off a tirade from Sounders coach Sigi Schmid after police escorted game officials off the field.

“I have no initial thoughts on this game,” said Schmid, who walked to the corner of the pitch before the final whistle. “I thought our guys played like lions. I thought they left their hearts out on the field. And I think they got robbed. Caleb (Timbers coach Porter) said last year at the end of the (Open Cup) game that it was the worst refereeing performance he had ever seen. I think it was topped this year. I walked away before I did something stupid.

“I think there was frustration certainly from our players. I don’t think Azira’s is a red card. And Dempsey, his reaction was what it was. On the same token, when a linesman tells you that a goal is not offsides because our defender played the ball to the guy . . . It looked to me like it was a shot that got deflected. You guys saw the game, and maybe you had the benefit of seeing a replay. But you’re telling me that Dylan Remick played him the ball? I don’t think so.

“Early on, I thought Portland was a little bit better than us. I thought after about 20 minutes we started to grab hold of the game and we were playing all right. For sure after they scored and made it 1-0, I thought we were all over them at that point and we created a number of chances to score goals.

“But then when you have calls that don’t seem to go your way . . . Their goal comes off a play where he’s ready to call a foul on Lamar Neagle when he gets stormed on and he doesn’t blow it. We move on.

“Brad Evans ends up getting a second yellow on something that initially is not a foul – Villafana just flops on the ball, handles the ball, and the foul’s on us. All of a sudden then, frustration, because he’s laying on top of the ball, so Brad’s trying to get to the ball because the referee’s not blowing the whistle.

“Well, if you’re laying on top of the ball, I know they don’t like to call obstruction, but that’s obstruction. And you’re not allowed to play the ball on all four, but this referee allowed it.”

U.S. Soccer has not indicated when, or to what degree, it will punish Dempsey, who is the captain of the U.S. Men’s National team.

The Sounders, with key operatives missing due to red cards, return to MLS play  Saturday against the San Jose Earthquakes. The CenturyLink match will kickoff at 1 p.m., PT and can be seen on JOEtv,